Autonomic robots have innumerable potential applications on both industrial and domestic levels. They are potentially capable of performing many mundane tasks which until now only human beings or other higher vertebrates have been capable of performing, to both increase productivity and improve quality of life. Such robots are particularly useful in applications which pose a hazard to living beings, for example in security functions, dealing with toxic materials, working in hazardous environments, and so on.
Many attempts have been made to design a self propelled autonomic robot, and to date the most successful designs have involved wheeled devices. However, wheeled devices have very limited utility in many environments. More than half of earth's landmass is impassable by wheeled vehicles of today's conventional size, let alone miniature or toy sized devices. Wheels are simply unsuitable in many environments, for example in rough or soft terrain. Moreover, any wheeled device is restricted to largely horizontal travel, since traction relies entirely on the force of gravity.
On the other hand, legged devices are capable of travelling on virtually any type of terrain. Such devices, although slower than wheeled devices, are far more versatile and adaptive to their environment, are capable of traversing obstacles that are impassable to wheeled devices, and if properly equipped are able to climb vertically. However, there are very few problems more difficult in modern robotics than building successful legged devices. Once the classic difficulties of mechanical power requirements, interconnection complexity and excessive weight are overcome, there remains the problem of control.
Autonomous legged creatures, to move and react effectively within their environment, require precise synchronizing control circuitry and the ability to adapt to new conditions as they arise. Until now, all attempts to create such a device have involved elaborate arrangements of feedback systems utilizing complex sensor inputs and extensive control and sequencing circuitry hard-wired to one or more central processors. Such a robot is extremely complex and expensive to build, even to accomplish very simple tasks. Moreover, due to the complexity of such a device and its heavy reliance on a central processing system power requirements are enormous, and a relatively minor problem, such as injury to a limb, is likely to cause total system failure. Such walking devices are accordingly impractical for other than experimental or educational uses.
The present invention overcomes these and other disadvantages by providing an autonomic limbed device utilizing a completely different control system approach. Rather than utilizing a central processor to process sensor information and responsively drive all mechanical processes, the device of the present invention utilizes a reconfigurable central network oscillator to sequence the processes of the devices limbs, each of which is itself autonomous. Once activated, each limb sequentially executes its processes independent of the central sequencer.
The present invention further provides a pulse delay circuit, with a delay of variable duration, which connected to a second pulse delay circuit acts as an artificial "neuron". The central and limb-actuating processes are achieved by a number of such "neurons" connected in series. The delay duration is determined merely by an analogue bias input to one or more "neurons", which may be controlled remotely or in response to local sensor stimulation. In a walking device, for example, differential delay patterns cause the device to deviate from a straight forward walking motion in some predetermined manner, and through many of the well-known walking gaits.
The advantages of this design are numerous. The pulse delay circuit is very inexpensive, to the extent that a fully autonomous four legged walking device incorporating the present invention can cost less than one hundred dollars to build, and all components are presently available "off the shelf". Power requirements are very small. The control circuits simplify mechanical process controls to mere pulse trains, requiring no microprocessor, so that if a microprocessor is utilized it can be virtually entirely dedicated to task planning and information retrieval. The process controllers are self-stabilizing, and since each limb is essentially autonomous it is unnecessary to hardwire all actuators and sensors to the central torso; moreover, if a limb is damaged or malfunctions it can be removed from the sequence automatically, without affecting the central sequencing processes or the operation of any other limb.
The inventor has termed this technology VSPANS, an acronym for "Very Slow Propagation Artificial Neural Systems", described in detail below.